We propose to determine the percentage of hepatic cells killed by 90 and 180 minutes of hemorrhagic shock. Of those cells remaining viable, changes in intracellular pH, cell volume, cell membrane potential, gluconeogenesis, protein synthesis, lipogenesis, and fine structure will be determined in the isolated rat hepatocyte from rats following a period of hemorrhagic shock and return of normal blood volume compared with normal unshocked rats. The numerous available techniques which demonstrate viability in the isolated hepatocyte will be adopted for this purpose. Following a precise definition of structural and functional changes in shock-injured hepatocytes, the effect of ATP-MgCl2 treatment in vivo and in vitro upon these parameters will be measured. The same techniques will be used to measure changes in shock-injured hepatocytes induced by cortisone, glucagon and dopamine therapy.